The present invention relates to disconnector contact drive devices for switchgear for power supply,and distribution, in movable pole units, so that in a first movement sequence, the disconnector contacts are separated from fixed mating contacts of the switchgear, and in a second movement sequence, the pole units are displaceable to yield the isolating distance, and the disconnect contacts are moved to disconnect them by force components acting in the x/y directions.
Disconnector contact drive devices of the above-identified type are described in German Patent Application 196 33 522. In a first movement sequence, the disconnector contacts are first moved out of the area of the fixed mating contacts of the switchgear, and then in a second movement sequence they displace the entire pole units to the extent that the isolating distances required for operator safety are reached.
In conjunction with operator safety, however, there are conventional switchgear panels having additional disconnect switches whose contact gaps form the required isolating distances.
In addition, with regard to the movability of the pole units, movable inserts with disconnect contacts have also been used, where the extent of their movability is also predetermined by the required isolating distances.
An object of the present invention is to provide a disconnector contact drive device which allows a compact design at minimal expense, but with which the drive energy to be expended is as low as possible and occurs largely uniformly over the entire movement process.
According to the present invention, this is achieved with the following features;
the disconnector contact drive devices are equipped with linear guide shafts,
the pole units contain pole box frames which are linearly movable along the guide shafts from an ON position stop to an OFF position stop due to the forces acting on the toggles,
the toggles each have four pivot bearings, with the first pivot bearing coupled to a linear actuator shaft, the second and third pivot bearings being bearings of the toggle, and the fourth pivot bearing connected to the pole box frame, and
the linear actuator shafts are connected to the rotary actuator shafts by corner gears.
The pole box frames are thus moved with the movable disconnect contacts in a straight line between the switch positions ON and switch positions OFF in parallel with the guide shafts. The disconnector contact drive devices of the pole box frames having toggles designed as four-bar linkage and the linear actuator and rotary actuator shafts that work together with them are implemented by, for example gears with a non-uniform transmission ratio controlling the movement processes of the pole box frames while maintaining the required isolating distances in two stages in the shortest paths in the switchgear.
Due to the special design of the toggles with their four toggle pivot bearings in conjunction with the linear actuator and rotary actuator shafts, the loads occurring non-uniformly over the entire movement sequences, results in a largely uniform load on the drives with the gears having a non-uniform transmission ratio.
The toggles which are completely extended in the ON switch positions also define the position of the pole box frames acting symmetrically and without reaction for the drives in the retracted state. Due to the non-uniform transmission ratios, the pole box frames are not moved at the start of rotation of the drive shafts, practically in the range of approx. 15xc2x0, so that in this phase the drives can be used to control auxiliary switches so that displays of faulty state information can be triggered promptly.
The gears formed from the toggles and the linear and rotary actuator shafts thus also function in transmission of the respective drive power, with these processes taking place in two successive steps.
According to an advantageous embodiment of the present invention,
the parts of the toggles that are movable about the third pivot bearing are engaged with a tension spring so that the force of the tension spring is effective in the ON position stop and in the OFF position stop.
The positions of the pole box frames in the retracted state are additionally stabilized by this measure. The tension springs also act as energy storage devices which supply increased drive forces on actuation of the disconnector contacts without any reaction effect on the actual drives and thus contribute toward further uniformization of the drive powers.
In another advantageous embodiment of the present invention,
the rotary actuator shafts are each connected to a drive motor.
In this way, the disconnector contact drive devices can be controlled by motors.
In another advantageous embodiment of the present invention,
the rotary actuator shafts can each be controlled by manually operable hand cranks.
Due to this measure, the rotary actuator shaft can be controlled independently of the system status of the switchgear.
In another advantageous embodiment of the present invention, provides the features:
the rotary actuator shafts are each coupled to a drive motor; and
the rotary actuator shafts can be controlled by manually operable hand cranks.
Thus, the rotary actuator shafts can be driven optionally by the drive motors and the hand cranks.